Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 69,717   Posts: 1,514,828   Online: 909
      
Page 4 of 4 FirstFirst 1234
Results 31 to 38 of 38
  1. #31
    SMBooth's Avatar
    Join Date
    Jun 2008
    Location
    Melbourne, North/West
    Shooter
    Multi Format
    Posts
    956
    Images
    7
    Quote Originally Posted by Darkroom317 View Post
    Also how far would the pinhole have to be away from the film?
    My 6x9 is 60mm focal length using a .3mm pinhole. Works fine

  2. #32

    Join Date
    Mar 2009
    Location
    University of Arkansas, Fayetteville
    Shooter
    Medium Format
    Posts
    591
    Quote Originally Posted by SMBooth View Post
    My 6x9 is 60mm focal length using a .3mm pinhole. Works fine
    Thanks for the reply. How would be the best way to go about making this pinhole? I do have access to an engraving laser.

  3. #33
    SMBooth's Avatar
    Join Date
    Jun 2008
    Location
    Melbourne, North/West
    Shooter
    Multi Format
    Posts
    956
    Images
    7
    Ive made quite good holes using a coke can a pin and 1200 grit sanding paper. .3mm is quite easy, but I use EMS laser pinholes that a friend form the US sent me. Will the laser you have access to do a single .3mm hole? if so get some thin brass or copper shimming material and whack a hole in it...
    Here how to do your own http://withoutlenses.com/view/drill-your-own

  4. #34

    Join Date
    May 2006
    Shooter
    Medium Format
    Posts
    775
    I would definitely try the engraving laser just to see if it can be done. What is the smallest spot you can make with that laser? Get some 0.001 inch thick brass or stainless steel shim stock and see if you can burn a tiny little hole. Last time I bought shim stock was from http://www.smallparts.com but since they turned into an Amazon store I have no idea if they still carry stuff like this. I would expect McMaster-Carr (http://www.mcmaster.com) will also have this, and maybe http://www.onlinemetals.com might have shim stock.

    The thinner the metal, the better the pinholes. The brass will be fairly fragile so be careful. The stainless should be relatively robust (considering the thickness we are talking about).

  5. #35

    Join Date
    Jan 2006
    Location
    Oklahoma
    Shooter
    Multi Format
    Posts
    588
    Attached is a generic plan for a pinhole design which I currently use. Being cupped outward allows you to burnish the plate down to minimal thickness at the pinhole. The thickness of the material that makes the pinhole is a critical parameter which is sometimes overlooked by the pinholer.

    Another area that can be overlooked is that a pinhole that is too small is just as bad as a pinhole that is too big. That is, if you are concerned with image sharpness.

    Cheers!
    Attached Thumbnails Attached Thumbnails Image1.jpg  
    Last edited by DannL; 06-28-2009 at 01:13 AM. Click to view previous post history.
    "Lo único de lo que el mundo no se cansará nunca es de exageración." Salvador Dalí

  6. #36
    BetterSense's Avatar
    Join Date
    Aug 2008
    Location
    North Carolina
    Shooter
    35mm
    Posts
    2,822
    That's pretty much what you end up with when you use a needle and a pop can, too, if you follow the popular method of dimpling the can and sanding it with fine sandpaper.
    f/22 and be there.

  7. #37

    Join Date
    Dec 2008
    Location
    Trinity, Alabama
    Shooter
    35mm
    Posts
    243
    Quote Originally Posted by WGibsonPhotography View Post

    To get 15.8 feet, I multiplied 746.5 by 10 to get 74.65cm. I then divided 74.65 by 2.54 to get 29.38in.

    That should actually say "to get 29.38in." I was trying to correct a mistake in math by taking out the numbers I screwed up and replacing them with the right ones. I just now caught that I didnt get the first 15.8 feet part. The edit button wasnt under the post tonight, and I dont know why :/

  8. #38
    Roger Thoms's Avatar
    Join Date
    Nov 2007
    Location
    San Francisco, CA USA
    Shooter
    4x5 Format
    Posts
    851
    Images
    7
    Here you go, no math involved. Glued a board in a 1 gal. paint can to hold the paper negative flat. Sprayed the inside of the can with flat black paint. Drilled a hole in the can with a #72 drill bit (I think) and the sanded with 400 grit sand paper to remove the burrs and hopefully thin the metal a bit. Here a an image from the camera (contact print from paper negative). http://www.pinholeday.org/gallery/2008/index.php?id=382

    Roger

Page 4 of 4 FirstFirst 1234


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin